(1) Field of the Invention
This invention relates to internal combustion engines and more particularly to compression ignition engines which use both liquid and gas fuels. (123/27GE)
(2) Description of the Prior Art
At the present time, there is on the market commercially, engines running on a combination of either natural gas or liquefied petroleum gas, and a liquid fuel herein called diesel. These engines were basically converted liquid engines having a regular liquid fuel injection system where the amount of fuel to be injected is controlled by the output of a governor. However, the amount of gas to be included as a fuel is primarily controlled by the amount of intake air through an air venturi system, similar to a spark ignition engine carburetor.
Before the original application was filed, the applicant caused a search to be made in the U.S. Patent and trademark Office. The following references were found in the U.S. Patent and Trademark Office and were reported by the searcher:
SHIRLEY, U.S. Pat. No. 2,555,818
NICHOLS, U.S. Pat. No. 2,681,049
DAVIDS, U.S. Pat. No. 2,708,916
STEIGER, U.S. Pat. No. 3,406,666
LAUBACH, U.S. Pat. No. 3,443,551
FOX, U.S. Pat. No. 3,540,419
HALBERG, U.S. Pat. No. 3,698,365
Of these patents HALBERG, NICHOLS, DAVIDS, SHIRLEY, and LAUBACH appear to increase the amount of diesel as well as increase the amount of gas as the total fuel is increased. FOX and STEIGER do not appear to operate upon this principle.
HALBERG uses a notched rod on the gas valve. DAVIDS uses a butterfly valve on the gas valve. SHIRLEY appears to increase the amount of gas by the length of time a gas poppet valve remains open. NICHOLS appears to use a manual control valve to adjust the amount of each fuel being used. LAUBACH discloses a valve having a piston with a series of drill holes in the valve cylinder wall.
In the prosecution of the original application, the Examiner cited:
RATHBUN, U.S. Pat. No. 2,502,990
SHIRLEY, U.S. Pat. No. 2,555,818
HAIDVOGEL, U.S. Pat. No. 3,753,424